Here is what I learned by reading Professional JavaScript for Web Developers:

When js stores a negative number, it does the following things:

get the binary representation of the absolute value of the negative number

replace 0s with 1s and 1s with 0s

add 1 to the result of step 2

So in my case -101 >> 1, we first convert -101 to its binary representation:

The binary representation of Math.abs(-101) is:

0000 0000 0000 0000 0000 0000 0110 0101

invert the 0s and 1s:

1111 1111 1111 1111 1111 1111 1001 1010

add 1 to the end:

1111 1111 1111 1111 1111 1111 1001 1011

Now, shift it to the right by 1:

1111 1111 1111 1111 1111 1111 1100 1101

The binary above should be the correct result of -101 >> 1, but when logging a negative number's binary representation, Javascript simply puts a negative sign in front of the binary representation of the positive number:

For our example, this means that when logging the result of -101 >> 1, JS will output minus sign + the binary representation of the positive number. But the positive number is not 101 >> 1 because 101 >> 1 gives you: